Group Dubey
Adaptive function of coloration in ectothermic vertebrates

An ectotherm’s body colour affects many facets of its existence, including fitness-relevant functions such as thermoregulation, foraging behaviour, metabolic physiology, and prey–predator interactions. Colour polymorphism within a population may thereby expand the range of environmental conditions under which at least some individuals are well-suited to meeting local challenges, even when those challenges vary considerably over small spatial and temporal scales. Body colour is likely to be especially significant for ectothermic animals, because of their reliance upon ambient conditions for thermoregulation. In particular, the relationship between an organism’s colour and the local environment is critical for ambush-foraging ectotherms, that rely upon background colour-matching to evade detection by potential prey. Thus, colour traits in such species will be subject to complex multifunctional optimisation. We are currently studying this problematic in the asp viper (Vipera aspis), which exhibit intrapopulational colour polymorphism in the Swiss Alps, with up to 70% of individuals being melanistic at high elevation.